Path Traversal in DeWeS Web Server (Twilight CMS)

Advisory ID: HTB23167
Product: DeWeS web server (Twilight CMS)
Vendor: Strata Technologies LLC
Vulnerable Version(s): 0.4.2 and probably prior
Tested Version: 0.4.2
Vendor Notification: July 24, 2013
Public Disclosure: August 21, 2013
Vulnerability Type: Path Traversal [CWE-22]
CVE Reference: CVE-2013-4900
Risk Level: Medium
CVSSv2 Base Score: 5 (AV:N/AC:L/Au:N/C:P/I:N/A:N)
Discovered and Provided: High-Tech Bridge Security Research Lab ( https://www.htbridge.com/advisory/ )

Advisory Details:

High-Tech Bridge Security Research Lab discovered path traversal vulnerability in DeWeS web server that is supplied in package with Twilight CMS (Windows version), which can be exploited to read arbitrary files on vulnerable system.

1) Path Traversal in DeWeS Web Server: CVE-2013-4900

The vulnerability exists due to insufficient validation of HTTP requests passed to web server. A remote attacker can send a specially crafted HTTP request containing directory traversal sequences (e.g. “…%5c”) and read arbitrary files on the target system with privileges of the user running the vulnerable web server.

The exploitation examples below use netcat tool to connect to remote web server in order to exploit the vulnerability using malicious HTTP GET request.

The first PoC (Proof of Concept) code displays contents of the "C:/windows/win.ini" file:

nc [host] 80
GET /…%5c…%5c…%5c…%5c…%5c…%5c…%5c…%5c…%5c…%5c/windows/win.ini HTTP/1.1

The second PoC code displays contents of the "userlist.dat" file that contains all Twilight CMS users and password hashes:

nc [host] 80
GET demosite/…%5c…%5c…%5c…%5c…%5c…%5c…%5c…%5c…%5c…%5c/TwilightCMS/Sites/company_site/Data/userlist.dat HTTP/1.1

Solution:

Currently we are not aware of any Vendor supplied patches or solutions.

<b>Vendor Notification Timeline:</b>
2013-07-24 Vendor notification via email
2013-07-25 Vendor notification via email
2013-08-02 Vendor notification via email and online web form
2013-08-09 Vendor notification via email and online web form
2013-08-12 Vendor notification via email and online web form
2013-08-21 No single answer from Vendor, public disclosure

References:

[1] High-Tech Bridge Advisory HTB23167 - https://www.htbridge.com/advisory/HTB23167 - Path Traversal in DeWeS
[2] DeWeS - www.stratek.ru - DeWeS is a small web server for developers of Twilight CMS.
[3] Common Vulnerabilities and Exposures (CVE) - http://cve.mitre.org/ - international in scope and free for public use, CVE® is a dictionary of publicly known information security vulnerabilities and exposures.
[4] Common Weakness Enumeration (CWE) - http://cwe.mitre.org - targeted to developers and security practitioners, CWE is a formal list of software weakness types.

Disclaimer: The information provided in this Advisory is provided "as is" and without any warranty of any kind. Details of this Advisory may be updated in order to provide as accurate information as possible. The latest version of the Advisory is available on web page [1] in the References.